AXIOM Beta

1 AXIOM Beta Topics

1.1 Active Battery Mount

Battery mount for NP-F970/F750/F550 batteries to power the AXIOM Beta. Includes power usage and capacity monitoring to estimate remaining charge and time remaining.

More Thoughts on Power.

1.1.1 InfoLithium Protocol

Proprietary protocol from Sony that exchanges metadata between batteries and devices. Expected data inside the protocol includes: charge cycles, battery ID, remaining total capacity, remaining current capacity, etc. Only official Sony batteries incorporate this protocol, cheap replacement parts don't and some Pro Sony cameras refuse operation with batteries without InfoLithium communication. Decrypting this protocol could give us more insight into the battery but is not essential as we can measure the discharge curve and estimate remaining capacity rather accurately that way.

1.1.1.1 Hacking References

http://randybuildsthings.wordpress.com/2013/02/25/sony-infolithium-m-teardown/

http://www.dpreview.com/forums/post/4296759

1.2 Dictator Remote Controller

https://apertus.org/dictator

Dictator

1.3 Image Processing Pipeline

Draft pipeline taken from AXIOM Alpha for now.

Image Acquisition Pipeline:

HDMI Image Processing Pipeline:

1.3.1 Image Processing Nodes

1.3.1.1 Debayering

A planned feature is to generate this FPGA code block with "dynamic reconfiguration" meaning that the actual debayering algorithm can be replaced at any time by loading a new FPGA binary block at run-time. This tries to simplify creating custom debayering algorithms with a script like programming language that can be translated to FPGA code and loaded into the FPGA dynamically for testing.

1.3.1.2 Image Overlays

Full HD framebuffer that can be altered from the Linux userspace and is automatically "mixed" with the real time video from the image sensor. (https://www.apertus.org/pong-project on the AXIOM Alpha was implemented exactly with this method)

We still need to decide if a color palette here is sufficient or how many colors we would need. 32 bit image with Alpha channel might be an unnecessary overkill here.

This feature could also be used to draw live histograms/scopes.

1.3.1.3 Peaking

Peaking marks high image frequency areas with colored dot overlays. These marked areas are typically the ones "in-focus" currently so this is a handy tool to see where the focus lies with screens that have lower resolution than the camera is capturing.

Handy Custom Parameters:

• color
• frequency threshold

Potential Problems:

• there are sharper and softer lenses so the threshold depends on the glass currently used. For a sharp lens the peaking could show areas as "in-focus" if they actually aren't and for softer lenses the peaking might never show up at all because the threshold is never reached

1.3.1.4 Image Blow Up / Zoom

Digital zoom into the center area of the image to check focus.

As extra feature this zoomed area could be moved around the full sensor area.

This feature is also related to the "Look Around" where the viewfinder sees a larger image area than is being output to the clean-feed.

This re-sampling method to scale up/down an image in real-time can be of rather low quality (nearest neighbor/bilinear/etc.) as it is only for preview purposes.

1.3.1.5 Matrix and LUTs

3x3 / 4x4 Matrix

AXIOM Alpha uses one LUT per color channel.

Maybe a 3D LUT (17×17×17) is possible at a later point: http://en.wikipedia.org/wiki/3D_lookup_table

1.4 IO Shields

1.4.1 Triple HDMI Output

Each port can deliver an independent 1080p60 4:4:4 stream with a different set of image processing nodes applied. Typically there will be one complete image processing pipeline and the three HDMI ports will output the real time image data from specific points in that processing pipeline.

1.5 Lens Mounts

Picture of a Nikon F bayonet mount.

Mount	Nikon F		Canon EF		Micro Four Thirds
Type	Bayonet
Compatible Lenses	Nikkor FX	Nikkor DX	EF	EF-S (optionally)
Image Circle Size	Full Frame ø 43.3 mm	DX ø 28.4 mm	Full Frame ø 43.3 mm	Canon APS-C ø 27.3 mm	"Half Frame" ø 21.6 mm
Throat	44 mm		54 mm		~38 mm
Flange focal distance	46.5 mm		44 mm		19.25 mm
Axiom Beta Sensor Compatibility	16mm Four Thirds Super35				16mm Four Thirds

More Details: Lens Mounts

1.5.2 Passive Nikon F-Mount

Measured Bayonet Thickness: 1.3mm

1.6 4K RAW PC recording option

1.7 Enclosure Design

Notes:

Body Design Options

Cooling

Switchable ND Filters not planned currently

Common and widely available peltier elements are 40x40mm (move it closer to fan?)

1.8 Electronics

1.8.1 AXIOM Beta PCB Stack Concept

Version 2:

Version 1:

Seen from the back side:

1.8.2 Image Sensor Frontend

It is planned to incorporate a glass filter slot between lens mount and lens base for placing an IR-cut-off filter or OLPF with IR-cut-off coating in the light path.

for Truesense KAC12040

Dimensions (inches if not stated otherwise):

1.8.2.1 Image Sensors

Graphic that compares the different Sensor Sizes and Lens Image Circles of the Axiom Beta

Axiom Beta Model	16mm	Four Thirds	Super35
Brand	CMOSIS	ON Semionductor (prev. Truesense/Kodak)	CMOSIS
Model	CMV2000	KAC12040	CMV12000
Type	CMOS
Shutter Type	Pipelined Global Shutter	Global & Rolling Shutter	Pipelined Global Shutter
Color filter Array	Bayer (Color model) None (B/W model)
IR filter	no
Anti-Aliasing Filter (OLPF)	no
Size	10.6 mm × 5.94 mm ø 12.1 mm	18.8 mm × 14.1 mm ø 23.5 mm	22.5 mm × 16.9 mm ø 28.2 mm
Crop Factor	Full Frame ∕ 3.56 16mm Film ∕ 1.05	Full Frame ∕ 1.84 Four Thirds ∕ 0.96	Full Frame ∕ 1.54 Super35 ∕ 1.10
Aspect Ratio	16:9	4:3	4:3
Pixel Resolution (h × v)	1920 × 1080	4000 × 3000	4096 × 3072
Pixel Size	5.5 µm	4.7 µm	5.5 µm
Dynamic Range	10 stops 15 stops (HDR mode)	9.3 stops (Gobal Shutter) 12 stops (Rolling Shutter)	10 stops 15 stops (HDR mode)
Sensitivity		200 ISO	~ 400 - 1250 ISO
Max Frame Rate @ Bit Depth	340 fps @ 10 bit 70 fps @ 12 bit	110 fps @ 8 bit 70 fps @ 10 bit 30 fps @ 12 bit 10 fps @ 14 bit	300 fps @ 10 bit 180 fps @ 12 bit
More info	Official Specs	Datasheet	Datasheet Official Specs Sensor Noise Analysis

1.8.3 IO Modules (Shields)

To be documented...

1.8.4 Dual Micro SD Module

This module adds two micro SD card slots to the AXIOM Beta. The active slot can be switched via the card driver and both cards share a 50MByte/s interface to the Zynq.

The bandwidth is not sufficient for video recording but more than enough for storing full resolution 4K raw still images.

The external slots can not be used for initial booting of the camera.

PCB Top	PCB Bottom

1.9 PCB Component Verification

Validation Guide:

PCB Component Footprint Validation Procedure

Boards:

axiom beta interface dummy v0.9

axiom beta sensor cmv12000 v0.13

axiom beta sensor cmv12000 v0.13 zif

axiom beta board 100 v0.15 test

axiom beta power board v0.4 test